This package provides a shareable ESLint configuration, used internally at Digita to adopt a uniform clean code style.

In the root of your (mono)repo, install @useid/eslint-config as a development dependency. From NPM v7 onwards,, this will automatically add the following peer dependencies as well (if you use an earlier version, install these yourself).

• eslint
• eslint-plugin-deprecation
• eslint-plugin-import
• eslint-plugin-jest
• eslint-plugin-jest-formatting
• eslint-plugin-jsdoc
• eslint-plugin-no-null
• eslint-plugin-prefer-arrow
• eslint-import-resolver-typescript
• @typescript-eslint/eslint-plugin
• lint-staged

When working in monorepo, install eslint as a development dependency in each subrepo as well.

In the root package.json, add the following eslintConfig and lint-staged objects.

"eslintConfig": {
  "extends": [
    "@useid/eslint-config"
  ]
}

"lint-staged": {
  "**/*.(js|ts)": [
    "eslint --fix"
  ]
}

Auto-fix-on-save functionality can be enabled with VSCode's dbaeumer.vscode-eslint plugin, using the following settings. It is enabled by default in our workspace files.

{
  "eslint.format.enable": true,
  "editor.defaultFormatter": "dbaeumer.vscode-eslint",
  "editor.codeActionsOnSave": {
    "source.fixAll.eslint": true
  }
}

The Prettier and EditorConfig projects also provide ways to ensure a uniform coding style. Often these are held to provide the visual style, limiting ESLint to lint for good coding practices. However, ESLint provides a lot more possibilities to fine-tune the visual aspect than either of these projects do. Moreover, all functionality provided by these projects can be subsumed by ESLint rules. We therefore adopt ESLint as a single point of truth. Rules subsuming functionality of Prettier (P) and EditorConfig (EC) have been indicated as such in comments.

For efficiency, either in your scripts or in you git hooks, you can run lint-staged, which is initially set up for .ts and .js files with eslint, but can be extended with different commands for other extensions.